1. Field of the Invention
The present invention generally relates to a method for forming a wiring pattern by laser irradiation, and in particular to a method using laser to irradiate a light-sensitive material to form a pattern and the irradiated light-sensitive material attaching metallic nano-particles to form a metallic wiring pattern.
2. The Prior Arts
Conventional printing methods for forming a wiring pattern on a substrate can be classified generally into a subtractive method and an additive method. The subtractive method generally uses photolithography or a pattern mask to etch a portion of a metallic layer on the substrate, thereby forming a wiring pattern. Subsequently, the photo-resist layer is removed. One of the disadvantages associated with this method is that it requires multiple electro-chemical processing steps such as electro-plating, chemical etching, chemical stripping, and cleaning, which produces a significant amount of chemical wastes that may be a source of pollution if the chemical wastes are discharged to the environment without proper post-treatment.
The additive method generally forms the metallic wiring pattern on the substrate by deposition techniques, such as evaporation deposition, sputtering deposition or chemical vapor deposition. However, the equipment utilized in the additive method is usually more expensive and takes more space. In addition, the additive method requires stricter processing conditions and processing environment. Moreover, proper maintenance of the equipment directly affects the quality of the products produced using the additive method, which requires a stricter control procedure.